How can two soft pieces of copper tubing of the same size be joined without fittings?

Swaging involves deforming the ends of two pieces of tubing to create a permanent connection without the need for fittings. This process is particularly effective for soft copper tubing, as the malleable nature of the material allows it to be compressed and reshaped easily. By inserting one end of the tubing into the other, the outer tubing can be swaged down onto the inner tubing, creating a tight seal that can withstand pressure and is leak-proof.

Soldering, welding, and brazing typically require either additional materials or high temperatures that are not ideal for soft copper. Soldering uses a filler material, welding requires melting the base metals, and brazing involves higher melting points. These methods may not be as efficient for joining soft copper tubing directly without fittings as swaging is.